This invention relates to ozone generators, and particularly to an ozone generator using a hot cathode tube wherein efficiency of the generator is increased by exciting oxygen flowing past the tube and mercury plasma within the tube is electromagnetically pinched in order to increase efficiency of the ozone generator.
Ozone generators utilizing mercury plasma tubes are well known. In these ozone generators, a transparent containment tube similar to a conventional fluorescent tube contains a mercury gas that when ionized by an electrical potential, becomes an electrically conductive plasma. This plasma emits ultraviolet light at one wavelength, 185 nanometers, that disassociates diatomic oxygen into atomic oxygen, each atom of which then combines with a molecule of diatomic oxygen to form an ozone molecule (O3). However, the mercury plasma also emits ultraviolet light at a wavelength of 254 nanometers, which tends to break down the ozone molecule, which then reverts back to diatomic oxygen. Since slightly more ozone is created than destroyed in a flow of oxygen (or air containing oxygen) past the plasma containment tube, the net result is that these type ozone generators typically generate about 500 parts per million of ozone in an airflow of about 1 liter/minute. In addition, the mercury plasma tubes used in ozone generators are operated at much higher power levels than a conventional fluorescent tube, which in turn generates higher operating temperatures of components of the containment tube. Contributing to this, during operation the plasma reaches to the inner walls of the containment tube, where many electrons impinge on the walls and lose energy, which increases losses. Because of heating from the increased power levels and the described losses, mercury plasma containment tubes are typically constructed of quartz, which requires a more expensive fabrication process than a conventional glass tube. Additionally, while high quality quartz readily passes ultraviolet radiation and glass generally blocks ultraviolet radiation, very thin glass tubes could be used where heating of the tube is not great. Such glass tubes would be much less expensive than conventional quartz tubes. Further, the components of the ozone generator holding a conventional quartz containment tube and components immediately surrounding the tube must be of heat resistant materials.
In view of the foregoing, it is one object of the invention to increase efficiency of an ultraviolet light ozone generator. It is another object of the invention to reduce operating temperatures of such an ozone generator. Yet another object of the invention is to reduce operational power requirements of the ozone generator. Other objects of this invention will become apparent upon a reading of the appended specification.
This invention is a hybrid ozone generator that utilizes ultraviolet light from a cold or hot cathode tube to produce ozone. An electrical field is disposed around the tube, the electrical field pumping energy into oxygen flowing past the tube. In addition, a theta pinch is performed on the plasma in the tube, causing an increase of radiation from the plasma. These effects together serve to increase efficiency of the ozone generator and allow more ozone to be generated while allowing the plasma containment tube to operate at lower temperatures.